Apparatus for production of stretch core yarns



0, 1969 w. J. HENRY 3,444,677

APPARATUS FOR PRODUCTION OF STRETCH CORE YARNS Filed June 19, 1963 INVENTOR.

WILLIAM J. HENRY BY z uwm aflum ATTORNEY United States Patent 3,444,677 APPARATUS FOR PRODUCTION OF STRETCH CORE YARNS William J. Henry, Greenville, S.C., assignor to Deering Milliken Research Corporation, Spartanburg, S.C., a

corporation of Delaware Filed June 19, 1963, Ser. No. 288,999 Int. Cl. D02g 3/32 U.S. Cl. 57-12 3 Claims ABSTRACT OF THE DISCLOSURE Apparatus for covering an elastic core yarn by drafting an inextensible textured fibrous roving and twisting the same about the core yarn, comprising a plurality of pairs of drafting rollers, traverse means for directing a strand of roving into the nip portion of the rollers while laterally moving the roving therebetween, and yarn guiding means operatively connected to the traverse means for movement therewith and adjustably positioned With respect thereto for guiding and continuously maintaining a running length of tensioned elastic core yarn on an edge of the ribbon-like strand passing into the nip portion of the front pair of drafting rollers, whereby the roving can be wrapped about the elastic core yarn so that the core yarn lies substantially uniformly at the axis of the composite yarn formed thereby.

This invention relates to the art of producing a composite stretch yarn. In particular, it relates to apparatus for producing stretch yarn by the spinning of non-elastic fibrous covering about an elastic core.

An important type of elastic yarn is one wherein an elastic core is covered with a nonstretchable or inextensible textile fibrous material. Such yarns are often formed by tensioning the elastic thread, constituting the core, and then spinning about the elastic thread or core an inextensible textile fibrous material. This is often done by feeding the tensioned elastic thread into the nips of a set of drafting rollers wherein a ribbon-like roving is matted or twisted about the elastic thread.

Elastic yarns of this type have met with wide commercial acceptance. Nevertheless, there is an inherent deficiency in such yarns inasmuch as shiners are manifested within the yarn, or within the fabric made from such yarn. Shiners are bright spots or gleaming streaks which show quite vividly in the yarn or fabric, especially after the yarn or fabric is dyed. These spots or streaks are obviously objectionable and degrade the quality of the yarn or fabric.

Shiners are produced at places in the yarn where the core grins through. This means that the elastic core, instead of being completely covered by the inextensible covering yarn lies exposed to the surface at some places. Such spots or streaks in the yarn are unsightly and degrade the yarn, or fabric. Also, where grinning occurs the dye is not uniformly applied in subsequent dyeing, or the dye does not color the spots or streaks at all so that these show as intensely bright spots or shiners.

Grinning occurs in present processes because the elastic yarn constituting the elastic core, is more or less randomly distributed throughout the yarn as it is manufactured. Thus, it does not necessarily lie at the axis of the yarn but varies in location from the surface of the yarn composite. Because of such randomness it is inevitable that the core will show through to the yarn surface at least on occasion so that grinning occurs.

Another acute problem in connection with the formation of such yarns is that related to the pickup of fly,

3,444,677 Patented May 20, 1969 ice particularly by the elastic or core yarn. Thus, core yarn especially possesses considerable affinity for and holds on to lint and other extraneous matter deposited thereon as a result of the inevitable atmospheric contamination common to mills. This is known as fly and the buildup of fly is referred to as slub formation. Slubs inevitably form within the yarn and adversely affect its quality. Such slubs form unsightly knots or kinks within the yarn, or fabric woven therefrom, and obviously their presence is very undesirable.

The presence of the larger slubs, in particular is intolerable and much be eliminated from the yarn. The only practical way of eliminating such slubs is by physically breaking the yarn part, removing the segment containing the slub, and tying the yarn back together. This technique is obviously likewise burdensome as, among other things, the presence of knots in the yarn is likewise unsightly. Slub formation is particularly onerous in present apparatus used by the textile industry in core spinning giving rise to all of these problems and many more.

Providing the art with means for the reduction or elimination of shiners and slubs is a truly Worthwhile objective and the attaining of such objective would represent a significant advancement in the state of the art.

It is, in fact, the primary objective of the present invention to provide the art with such means for the amelioration or substantial elimination of shiners and slubs and, accordingly, to provide a new and improved apparatus which will upgrade the quality of stretch yarn made by the spinning of a nonelastic fibrous covering about an elastic core. In particular, it is an object to provide a new and novel apparatus for producing an improved quality stretch type yarn, especially one wherein an inextensible fibrous covering is spun about an elastic core so that the core remains substantially at the axis or at the center of a given cross section of the yarn strand. More particularly, it is an object to provide a new traversing yarn core spinning apparatus for fixed relative positioning between the core yarn and the roving which is useful for the reduction of grinning and elimination of slubs. These objects, and others, will be apparent in view of the following description of the invention.

Composite yarns of superior quality can be formed upon the apparatus of this invention which provides means for the relative positioning of the core yarn and roving even while these materials are traversed through a series of several pairs of drafting rollers. Thus, guide means are so disposed in relation to the rollers that, even while the roving is gradually laterally displaced to and fro upon the rollers there is supplied via the guide means a running length of tensioned elastic core yarn which is maintained upon an edge of a running length of ribbon-like roving, while the opposite edge of the ribbon-like roving is twisted radially about the elastic yarn. When the roving is given a Z twist the stretched elastic yarn is placed and maintained at the upper left edge of the roving and, conversely, when given an S twist the elastic yarn is placed and maintained at the upper right edge of the roving. This is sharply contrasted with practice wherein the running length of elastic yarn is deliberately aligned upon the center of the running length of a ribbon-like roving whether an S twist or Z twist is applied. The present apparatus is not only admirably suited for maintaining this desired relation between the core yarn and ribbon-like roving to eliminate grinning but also drastically reduces and virtually eliminates slubs which normally impair and reduce, directly or indirectly, the quality of the yarn. Indeed the difference in the quality of the elastic yarn composite obtained pursuant to this invention vis-a-vis that of the prior art is indeed striking. Moreover, the apparatus functions smoothly and efiiciently as a result of slub elimination.

The invention will be more fully understood in view of the following detailed description which makes reference to the drawing wherein:

FIGURE 1 shows a diagrammatic view of apparatus for applying an inextensible textile fibrous covering to a tensioned core yarn;

FIGURE 2 shows a front view of the apparatus and the positioning of the core yarn where a Z twist is applied;

'FIGURE 3 shows also a front view of the apparatus and the positioning of the core yarn when an S twist is applied;

FIGURE 4 is a sketch showing the principle of spinning the ribbon-like roving about an elastic core as when a Z twist is applied; and

FIGURE 5 is a sketch which demonstrates the principle when an S twist is applied.

Referring to FIGURE 1 there is shown apparatus including a plurality of pairs of drafting rollers (rotated by means not shown) including at least a front pair of rollers 11, 12 and a back pair of rollers 15, 16 between the nips of which is drafted and forwardly progressed a substantially inextensible textile fibrous roving 30. The roving 30 is combined with an elastic core yarn 10, the latter contacting the former behind the front pair of rollers 11, 12 where begins the formation of a composite elastic yarn by the wrapping of the flattened ribbon-like roving 30 about the core yarn 10.

In the embodiment shown, the roving 30 is brought through a series of three pairs of drafting rollers; a back pair of rollers 15, 16; a middle pair of rollers 13, 14; and a front pair of rollers 11, 12. The rollers are supported for rotation by shafts 25, which are rotatably driven by conventional means, not shown. The core yarn is provided just behind the front pair of rollers 11, 12 and is maintained in fixed relative position with the roving which is reduced to a ribbon-like strand between the front pair of rollers 11, 12 and middle pair of rollers 13, 14. The core yarn 10 is placed upon an upper edge of the ribbon-like roving 30-i.e. upon the upper left edge if a Z twist is to be applied as in FIGURES 1 and 2 or upon the upper right edge if an S twist is to be applied, as in FIGURE 3. The ribbon-like roving 30 and core yarn 10 are, in this fashion, passed between the pair of rollers 11, 12 after which time twist is applied.

The roving 30 is caused to traverse to some extent the width of the individual rollers as it passes through the series of drafting rollers. The roving 30, from supply package 28, is thus introduced to the drafting rollers via trumpet 17. The trumpet 17 is rigidly attached upon the traversing frame 18, which moves laterally back and forth to feed the roving to the drafting rolls. Between the pair of back rolls 15, 16 and the middle pair of rolls 13, 14, the friction of the roving bondage of roving 30 is broken by the diiferential speeds of these rollers. Between the middle pair of rolls 13, 14 and front pair of rolls 11, 12, the roving 30 is spread into a ribbon-like formation, and it is here that the core yarn 10 is introduced and applied upon an edge of the ribbon-like roving 30. The relative position of the core yarn 10 upon an edge of the ribbon-like roving 30 is maintained at all times during operation because the core yarn 10 is made to traverse simultaneously with the ribbon-like roving 30 which traverses in harmony with traversing frame 18. Thus, any preselected setting or relative positioning between the core yarn 10 and ribbon-like roving 30 will be maintained throughout operation.

The core yarn 10 is introduced upon the ribbon-like roving 30 by passage over the guide wheel 20 which is mounted upon bracket 23 aflixed to arm 19. Guide wheel 20 can be set so as to be precisely aligned with, and will traverse with traversing frame 18 since it is mounted therewith by means of the rigid arm 19. Guide wheel 20 can be adjusted for any preselected setting as by movement in a direction parallel with the uppermost portion of arm 19 by rotation of nut 22, which moves the threaded bolt 21 into and out of bracket 23. A similar nut (not shown) on the opposite side of bracket 23 permits tightening of the threaded bolt 21 in fixed position. Guide wheel 20 is also laterally movable in regard to arm 19 by movement within the lateral slot 24. The tightening of the threaded bolt 21 in fixed lateral position is also conveniently performed by sequentally loosening of the nut 22, sliding the bolt 21 within the slot 24 and then tightening the nut 22 when the bolt 21 is in the desired position.

The core yarn 10 is introduced to the ribbon-like strand of roving 30 from supply roll 27, which is driven by a roller 26. A differential peripheral speed is provided between the drive roll 26 and the peripheral speed of the front pair of rollers 11, 12 to maintain a constant preselected tension upon the core yarn 10. Thus, tension is applied and maintained upon the core yarn 10 by providing a constant but lesser peripheral speed for the drive roll 26 than for front rollers 11, 12.

The principle of the invention is conveniently demonstrated by references to FIGURES 4 and 5. When a Z twist is applied to from the composite yarn as in FIGURE 4, the core thread 10 is placed upon the upper left edge of the ribbon-like roving 30. The roving is then picked up and radially moved about, in counterclockwise direction, the core yarn 10 which lies as an axis at the center of motion. On the other hand, where an S twist is applied as in FIGURE 5, the core yarn 10 is placed upon the upper right edge of the ribbon-like roving 30 and the latter picked up and rotated in a clockwise motion, the core yarn 10 lying as an axis at the center of rotation.

When actual runs are made using differential speeds between the back and middle pairs of rollers of -1:1.-67 and between the middle and front pairs of rollers of 1.67:43.6, when a denier polyurethane strand is used as the core yarn and when cotton roving is employed grin through is drastically reduced as compared with similar runs wherein the core yarn is fed into the center of the ribbon-like strand.

Although the core yarn guide arm 19 and adjustable guide wheel 20 of the present invention are shown and described as being positioned above the drafting rolls to receive the core yarn 10 from the supply package 27 located above the rolls, it is obvious that the supply of core yarn could be located below the drafting rolls with the arm and guide extended'beneath and positioned below the drafting rolls to guide the core yarn into proper relationship on the lower surface edge portion of the ribbon-like strand of roving; therefore, the use of the term on in referring to the position of the core yarn with respect to the strand of roving in the present specification and claims is intended to include placement of the core yarn either on the upper or lower surface of the ribbon-like strand of roving.

Having described the invention, what is claimed is:

1. Apparatus for covering an elastic core yarn by drafting an inextensible textured fibrous roving and twisting the same about the core yarn comprising a plurality of pairs of drafting rollers including a front and a back pair of rollers for receiving a fibrous roving between the nips thereof,

means for rotating said drafting rollers to draft roving passing therethrough and to form a ribbon-like strand of roving at the entrance of the nip portion of said front pair of rollers, traverse means located behind said drafting rollers for guiding and laterally moving the roving between the nip portions of the rollers during drafting, and

means for supplying a tensioned elastic core yarn to nip portion of the front pair of rollers for movement with and generally parallel to movement of roving therethrough,

said means including yarn guiding means operatively connected to said traverse means for movement therewith, said yarn guiding means being adjustably positionable with respect to said traverse means for guiding and continuously maintaining a running length of tensioned elastic core yarn on either edge of the ribbonlike strand of roving passing into the nip portion of the front pair of rollers, whereby the roving can be wrapped about the elastic core yarn so that the core yarn lies substantially uniformly at the axis of a composite yarn formed from the roving and elastic core yarn.

2. Apparatus as defined in claim 1 wherein said traverse means includes a traverse frame and a roving guide mounted thereon; and wherein said yarn guiding means includes an arm member attached to said traverse frame with its outer end disposed adjacent the nip portion of said front drafting rollers, and a yarn guide element adjustably secured to the outer end of said arm member for horizontal positioning thereof with respect to said roving guide.

3. Apparatus as defined in claim 2 wherein the outer end portion of said arm member has a generally horizontally extending slot therein, said yarn guiding means further includes a threaded bolt disposed in and adjustably positionable along said slot, and said guide element comprises a guide wheel rotatably mounted on said threaded bolt such that the guide wheel is horizontally adjustable for preselected positioning of tensioned core yarn on an edge of a roving passing into the nip portion of said front pair of rollers.

References Cited UNITED STATES PATENTS 1,198,997 9/1916 Cunningham 57-12 X 2,024,156 12/1935 Foster 57-36 X 2,036,778 4/1936 'Shenck 57-12 2,210,884 8/1940 Chittenden et al 57-12 X 2,588,361 3/1952 Cooper 57-152 2,953,893 9/1960 Smith et al 57-36 2,971,322 2/1961 Bouvet 57-136 X 3,092,953 6/ 1963 Blackstock 57-36 753,625 2/1904 Prest t 57-111 1,286,311 12/1918 Heathcock 57-12 2,890,565 6/ 1959 Wright et al. 57-106 FOREIGN PATENTS 1,227,375 2/ 1960 France.

JOHN PETRAKES, Primary Examiner.

US. Cl. X.R. 57-152, 163 

